2-210637752-C-T

Position:

• chr2-210637752-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2 PP3_Strong PP5

The NM_001875.5(CPS1):​c.2738C>T​(p.Ser913Leu) variant causes a missense change. The variant allele was found at a frequency of 0.00000479 in 1,461,720 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: CPS1 NM_001875.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 6.95

Genes affected

CPS1 (HGNC:2323): (carbamoyl-phosphate synthase 1) The mitochondrial enzyme encoded by this gene catalyzes synthesis of carbamoyl phosphate from ammonia and bicarbonate. This reaction is the first committed step of the urea cycle, which is important in the removal of excess urea from cells. The encoded protein may also represent a core mitochondrial nucleoid protein. Three transcript variants encoding different isoforms have been found for this gene. The shortest isoform may not be localized to the mitochondrion. Mutations in this gene have been associated with carbamoyl phosphate synthetase deficiency, susceptibility to persistent pulmonary hypertension, and susceptibility to venoocclusive disease after bone marrow transplantation.[provided by RefSeq, May 2010]

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.962
• PP5: Variant 2-210637752-C-T is Pathogenic according to our data. Variant chr2-210637752-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 558211.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1}. Variant chr2-210637752-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CPS1	NM_001875.5	c.2738C>T	p.Ser913Leu	missense_variant	22/38	ENST00000233072.10	NP_001866.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CPS1	ENST00000233072.10	c.2738C>T	p.Ser913Leu	missense_variant	22/38	1	NM_001875.5	ENSP00000233072	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000796 AC: 2 AN: 251354 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135852

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000653

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461720 Hom.: 0 Cov.: 31 AF XY: 0.00000688 AC XY: 5 AN XY: 727150

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000696

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Congenital hyperammonemia, type I Pathogenic:1 Uncertain:1

Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	May 10, 2018	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Mar 14, 2024	Variant summary: CPS1 c.2738C>T (p.Ser913Leu) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 8e-06 in 251354 control chromosomes (gnomAD). c.2738C>T has been reported in the literature in individuals affected with Carbamoylphosphate Synthetase I Deficiency (Haberle_2011, Makris_2021). These data indicate that the variant may be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function, finding that the variant drastically decreased the yield of pure CPS1 and specific enzyme activity (Diez-Fernandez_2014). The following publications have been ascertained in the context of this evaluation (PMID: 21120950, 24813853, 33309754, 35003817). ClinVar contains an entry for this variant (Variation ID: 558211). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.60
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.57
CADD	Pathogenic	27
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.97	.;D;.
Eigen	Pathogenic	0.90
Eigen_PC	Pathogenic	0.81
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	D;D;D
M_CAP	Pathogenic	0.33	D
MetaRNN	Pathogenic	0.96	D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.0	.;H;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.61	T
PROVEAN	Pathogenic	-4.9	D;D;D
REVEL	Pathogenic	0.95
Sift	Pathogenic	0.0	D;D;D
Sift4G	Pathogenic	0.0	D;D;D
Polyphen		1.0	.;D;.
Vest4		0.95
MutPred		0.79		.;Loss of disorder (P = 0.0259);.;
MVP		0.98
MPC		0.58
ClinPred		1.0	D
GERP RS		5.5
Varity_R		0.96
gMVP		0.90

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.14		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs754706559; hg19: chr2-211502476;